The Relationship Between the Acute Changes of the Systolic Blood Pressure and the Brachial-Ankle Pulse Wave Velocity

BACKGROUND: The brachial-ankle pulse wave velocity (baPWV) is a useful parameter to assess arterial stiffness. However, it is difficult to evaluate arterial stiffness in hypertensive patients because the baPWV is affected by the blood pressure itself. This study was designed to estimate the relationship between the change of the blood pressure parameters and the baPWV (ΔbaPWV) when hypertensive patients were subjected to an acute reduction of blood pressure. METHODS: Thirty patients with essential hypertension and whose blood pressure was higher than 140/90 mmHg were enrolled. In all the patients, the blood pressure and baPWV were measured using an automatic waveform analyzer with the patients at a resting state. When the reduction of blood pressure was more than 10 mmHg after sublingual administration of nifedipine 10 mg, then the blood pressure and baPWV were measured again in the same manner and then they were compared with the baseline values. Spearman's correlation and multiple linear regression tests were performed to estimate the relationship between the change of the blood pressure parameters (ΔSBP, ΔDBP, ΔMAP and ΔPP) and the ΔbaPWV. RESULTS: The baPWV was significantly decreased shortly after the administration of nifedipine (1903.6±305.2 cm/sec vs. 1716±252.0 cm/sec, respectively, p<0.01). The ΔbaPWV was correlated with the ΔSBP (r=0.550, p<0.01), ΔDBP (r=0.386, p<0.05), ΔMAP (r=0.441, p<0.05), and ΔPP (r=0.442. p<0.05). On the multiple regression analysis, the ΔSBP was the only significant variable for predicting the ΔbaPWV, and the linear equation was ΔbaPWV=8.7×SBP-48. CONCLUSIONS: The baPWV is affected by the systolic blood pressure level to a large degree and careful attention must be paid to the blood pressure level when evaluating arterial stiffness with using the baPWV.